When you start undoing some bolts and screws to take the motor out the window will start to sag. If you take enough of them out the window will come all the way down. I think this is why they FSM states to put the window down. It is not a big deal.

I took the front passenger side out when the window was stuck up on my SD. The motor was stuck. I took it apart and relubed everything I could. Put it back together and it has been working for over a year.

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2009 ML320 Bluetec
1985 300CD
1981 300TD

Past Mercedes
1979 300TD
1982 300TD
2000 E320 4Matic Wagon
1998 E430
1984 300SD
1980 300SD